Organic secondary battery

ABSTRACT

An organic secondary battery comprising an anode including an anode-active material, a cathode including a cathode-active material and an electrolytic medium, in which at least the cathode-active material consists essentially of a benzene polymer, and a method of producing the benzene polymer by electrolytic polymerization with anodic oxidation of a benzene or benzene derivative monomer in an electrolytic solution.

This is a division of application Ser. No. 07/219,869, filed on July 12, 1988, now U.S. Pat. No. 4,935,319, which is a continuation of Ser. No. 06,866,927, filed on May 27, 1986 now abandoned.

BACKGROUND OF THE INVENTION

The present invention relates to an organic secondary battery and more particularly to a non-aqueous organic secondary battery.

Recently many different types of organic secondary batteries using as cathode-active and/or anode-active materials polymeric materials having conjugated double bonds.

For instance, in J. Chem. Soc., Chem. Commun., (1982) 361-362, an organic secondary battery using polyphenylene as its active materials is proposed The polyphenylene reported in this reference was prepared by a chemical polymerization method and was in the form of powder. In order to use the powder-like polymer as active-material in a thin-type battery, it was necessary to work the powder-like polymer into a film. The thus prepared polyphenylene film, however, has the drawbacks that the self-discharge is great and the film working process is not easy.

In order to use polymeric materials having conjugated double bonds as cathode-active material, it is necessary that the polymeric materials have the property of allowing N-type doping. Polymeric materials capable of allowing such N-type doping, however, are limited to particular materials such as polyacetylene, poly para-phenylene and polythiophene. When these polymers are employed as cathode-active material, polyacetylene has the shortcoming that it is unstable when worked into a film, poly para-phenylene is in the form of powder and therefore must be worked into a film, but the obtained film is poor in flexibility, and polythiophene has the shortcoming that the self-discharge is great. In short, these polymers are not suitable for use as cathode-active material of organic secondary batteries and thin-type batteries. Under such circumstances, an organic secondary battery of a light and thin type having high stableness and minimized self-discharge has not been available yet.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide an organic secondary battery of a light and thin type which is free from the above shortcomings of the conventional organic secondary batteries and pollution problems and has high energy density.

Another object of the present invention is to provide an organic secondary battery with at least its cathode-active material comprising a benzene polymer film having high stableness and minimized self-discharge, which is prepared by polymerizing a benzene or benzene derivative monomer by electrolytic polymerization.

Still another object of the present invention is to provide an organic secondary battery with its cathode-active material comprising the above-mentioned benzene polymer and its anode-active material comprising a polypyrrole film which is prepared by polymerizing pyrrole by electrolytic polymerization.

A further object of the present invention is to provide an organic secondary batttery of the above-mentioned type having a separator comprising a polyfuran complex between its cathode and anode.

A further object of the present invention is to provide a method of polymerizing a benzene or benzene derivative monomer to produce the above-mentioned benzene polymer by electrolytic polymerization.

The electrolytic polymerization can be carried out in an electrolytic polymerization system including an electrolytic solution of a benzene or benzene derivative monomer, an electrolyte dissolved in a solvent, with a cathode and an anode immersed in the solution. The electrolytic polymerization is performed with anodic oxidation by causing an electric current to flow through the above system. In this electrolytic polymerization, in addition to conventional electrolytes, catalysts for Friedel Crafts reaction and electrolytes capable of producing Lewis acids in the presence of a transition metal complex can be employed.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings,

FIG. 1 is a schematic illustration of an electrolytic polyermization system for preparing a benzene polymer for use in an organic secondary battery according to the present invention.

FIG. 2 is an IR spectrum of a benzene polymer film No. 5.

FIG. 3 is an IR spectrum of an undoped benzene polymer film No. 5.

FIG. 4 is a schematic illustration of an organic secondary battery according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An organic secondary battery according to the present invention comprises an anode, a cathode and an electrolytic medium. When necessary, the anode and cathode each can include a current collector. A separator can also be interposed between the cathode and the anode. As the electrolytic medium an electrolytic solution comprising a solvent and an electrolyte can be employed Instead of the electrolytic solution, a solid electrolyte can also be employed.

The cathode comprises a cathode-active material, and the anode comprises an anode-active material. The cathode-active material and the anode-active material are respectively doped with a cation and an anion for storing electric energy therein and the stored energy is discharged through the external circuit which connects the cathode and the anode.

As the electrolytes of the electrolytic solution, for example, salts comprising the following anion dopants and cation dopants can be employed:

(1) Anion dopants: halogenated anions of Va-group elements, such as PF₆ ⁻, SbF₆ ⁻, AsF₆ ⁻ and SbCl₆ ⁻ ; halogenated anions of IIIa-group elements, such as BF₄ ⁻ ; and perchlorate anions such as ClO₄ ⁻.

(2) Cation dopants: alkali metal ions such as Li⁺ and K⁺ ; and tetraammonium ions such as R₄ N⁺ (where R represents a hydrocarbon group having 1 to 20 carbon atoms)

The above anion dopants provide an N-type electroconductive conjugated polymer, while the cation dopants provide a P-type polymer in the battery.

Specific examples of the above electrolytes capable of providing the above dopants are as follows: LiPF₆, LiSbF₆, LiAsF₆, LiClO₄, NaClO₄, KI, KPF₆, KSbF₆, KAsF₆, KClO₄, [(n-Bu)₄ N]⁺. (AsF₆)⁻, [(n-Bu)₄ N]⁺. ClO₄ ⁻, LiAlCl₄, LiBF₄, where Bu represents a butyl group.

As the solvents for the electroylytic solution, polar non-protonic solvents having high specific dielectric constant, for example, ketones, nitriles, esters, carbonates, nitro compounds, sulfolane-type componds and lactone-type compounds, can be employed Of these compounds, nitriles, carbonates, sulfolane-type compounds and lactone-type compounds are preferable for use. Specific examples of these compounds are acetonitrile, propionitrile, butyronitrile, valeronitrile, benzonitrile, ethylene carbonate, propylene carbonate, Y-butyrolactone, sulfolane and, 3-methylsulfolane.

In the present invention, at least as the cathode-active material, a benzene polymer is employed. In the present invention, the term "benzene polymer" means not only linear polymers such as polyphenylene, but also planar polymers such as polyacene and polyacenone.

The benzene polymer for use in the present invention is prepared by polymerization of a benzene or benzene derivative monomer. The benzene monomer is benzene, and a benzene derivative monomer is, for example, diphenyl, halogenated benzene and halogenated diphenyl.

It is preferable that a benzene polymer film be prepared by an electrochemical method. A general electrochemical method is described, for instance, in J. Electrochem. Soc., Vol. 130, No. 7 1506˜1509 (1983), Electrochimica Acta, Vol. 27, No. 1. 61˜65 (1982) and J. Chem. Soc., Chem. Commun, 1199 (1984).

In the present invention, the above polymerization is performed by placing an electrolytic solution of the above-mentioned benzene or benzene derivative monomer, an electrolyte and a solvent in an electrolytic chamber, immersing a cathode and an anode in the solution, followed by electrolytic polymerization with anodic oxidation by causing an electric current to flow through the electrolytic solution.

As such electrolytes, (i) conventional electrolytes such as LiPF₆, LiSbF₆, LiAsF₆, LiClO₄, NaClO₄, KI, KPF₆, KSbF₆, KAsF₆, KClO₄, AgBF₄, NaBF₄, NaAsF₆, NaPF₆, [(n-Bu)N]⁺. (AsF₆)⁻, [(n-Bu)₄ N]⁺. ClO₄ ⁻, (ii) catalysts for Friedel Crafts reaction, such as FeCl₃, AlCl₃, ZnCl₂ and AlBr₃, and (iii) electrolytes containing an anion capable of producing a Lewis acid in the presence of a transition metal complex. When the Friedel Crafts catalysts are employed, it is considered that the complex or reaction product of the employed solvent and the catalyst works as electrolyte.

When benzene is employed as the monomer, the above Friedel Crafts catalysts and mixtures of the catalysts and other electrolytes are effective for the polymerization reaction.

As the solvent, for example, acetonitrile, benzonitrile, propylene carbonate, γ-butyrolactone, dichloromethane, dioxane, dimethylformamide, and nitro compound solvents such as nitromethane, nitroethane, nitropropane and nitrobenzene (each having a doner number of less than about 10) can be employed.

When benzene is employed as the monomer, the above nitro compound solvents having such small doner numbers are preferable for use.

As the materials for constructing the electrodes, for the electrolytic polymerization, metals such as Au, Pt and Ni and metal oxides such as SnO₂ and In₂ O₃ can be employed. Further composite electrodes and coating electrodes comprising the above metal oxides can also be employed. It is preferable that the anode be made of the metal oxide for obtaining a benzene polymer film having high strength.

For electrolysis, constant-voltage electrolysis, constant-current electrolysis and constant-potential electrolysis can all be employed. Of these, constant-current electrolysis and constant-potential electrolysis are most suitable. In particular, constant-current electrolysis is suitable for mass production.

In the electrolysis, the adjustment of the current density is important since it has a significant effect on the morphology of the polymeric film to be made. Therefore it is necessary to make fine adjustment of the current density by appropriate combination of the electrolytes.

The thus produced benzene polymer is in the form of a film having a thickness of about 1000 μm or less and is electrochemically active. Therefore it is useful as cathode-active material. In particular, a benzene polymer having a structure grown in the form of a layer has a great specific area, allows N-type doping and is stable. Therefore it is preferable for use as cathode-active , material. The benzene polymer can also be employed as anode-active material.

Active Material Preparation Example 1

In an electrolytic chamber provided with an anode of Nesa glass (30 Ω/cm²) and a cathode of Ni as shown in FIG. 1, an electrolytic solution of benzene (0.1M) and anhydrous aluminum chloride (0.2M) dissolved in nitromethane was placed. Constant-current electrolysis with 25 mA/cm² was performed, so that a benzene polymer film No. 1 was prepared on the Nesa glass as shown in FIG. 1.

Active Material Preparation Example 2

In the same electrolytic chamber provided with the anode of Nesa glass (30 Ω/cm²) and the cathode of Ni as that employed in Active Material Preparation Example 1, an electrolytic solution of benzene (0.1M) and anhydrous aluminum chloride (0.2M) dissolved in nitrobenzene was placed. Constant-current electrolysis with 20 mA/cm² was performed, so that a benzene polymer film No. 2 was prepared.

Active Material Preparation Example 3

In the same electrolytic chamber provided with the anode of Nesa glass (30 Ω/cm²) and the cathode of Ni as that employed in Active Material Preparation Example 1, an electrolytic solution of benzene (0.05M) and anhydrous aluminum chloride (0.1M) dissolved in nitromethane was placed. Constant-current electrolysis with 35 mA/cm² was performed, so that a benzene polymer film No. 3 was prepared.

Active Material Preparation Example 4

In the same electrolytic chamber provided with the anode of Nesa glass (30 Ω/cm²) and the cathode of Ni as that employed in Active Material Preparation Example 1, an electrolytic solution of benzene (0.1M) and iron chloride (0.1M) dissolved in nitromethane was placed. Constant-current electrolysis with 20 mA/cm² was performed, so that a benzene polymer film No. 4 was prepared.

In addition to the polymerization method using the above Friedel Crafts catalysts, a polymerization method using a boron trifluoride complex as Lewis acid is capable of yielding a thick and uniform benzene polymer film for use in the present invention.

Specific examples of a boron trifluoride complex are BF₃ methanol complex, BF₃ ethanol complex, BF₃ propanol complex, BF₃ dimethyl ether complex, BF₃ diethyl ether complex, BF₃ phenol complex and BF₃ acetic acid complex.

As electrolytic solvents for this polymerization method, non-protonic solvents, such as acetonitrile, benzonitrile, propylene carbonate, γ-butyrolactone, dichloromethane, dichloroethane, dimethylformamide, nitromethane, nitroethane and nitrobenzene, can be employed.

The most appropriate polymerization system for this method is a system of BF₃ ether complex as Lewis acid and a solvent having a small doner number (about 10 or less) (for example, nitromethane, nitroethane, nitrobenzene, dichloroethane and dichloromethane). By this system, a high quality benzene polymer film with can be obtained.

As the monomer for the benzene polymer, for example, benzene, diphenyl, and halogenated benzene and diphenyl are preferable for use.

The above polymerization is performed by placing a solution comprising one of the above-mentioned monomers, the Lewis acid, and the solvent in an electrolytic chamber, immersing a cathode and an anode in the solution, followed by electrolytic polymerization with anodic oxidation by causing an electric current to flow therethrough.

When necessary, electrolytes and other catalysts can be added to the polymerization system.

As such electrolytes, LiPF₆, LiSbF₆, LiAsF₆, LiClO₄, NaClO₄, KI, KPF₆, KSbF₆, KClO₄, AgBF₄, NaBF₄, NaAsF₆, NaPF₆, [(n-Bu)₄ N⁺ ]. (BF₄)⁻, [(n-Bu)₄ N⁺ ].(AsF₆)⁻ and [(n-Bu)₄ N]⁺. ClO₄ ⁻ are preferable for use.

Further, it is preferable that water and oxygen be eliminated as much as possible from the polymerization system for extending the pot life of the polymerization solution. The quality of the benzene polymer film is not significantly affected even if the polymerization is carried out in such a condition as to be exposed to the air.

As the materials for constructing the electrodes for the electrolytic polymerization, metals such as Au, Pt and Ni and metal oxides such as SnO₂ and In₂ O₃ can be employed. Further composite electrodes and coating electrodes comprising the above metal oxides can also be employed. It is preferable that the anode be made of the metal oxide for obtaining a polymer film having high strength.

For electrolysis, constant-voltage elecrtrolysis, constant-current electrolysis and constant-potential electrolysis can all be employed. Of these, constant-current electrolysis and constant-potential electrolysis are most suitable. In particular, constant-current electrolysis is suitable for mass production.

In the electrolysis, the adjustment of the current, density is important since the current density has a significant effect on the morphology of the obtained film. Therefore it is necessary to make fine adjustment of the current density by appropriate combination of the electrolytes.

This polymerization method is completely safe since no poisonous gases such as boron trifluoride and fluorine are generated in the course of polymerization. Further this method is capable of yielding a benzene polymer in a stable manner.

Immediately after the polymerization, the obtained benzene polymer film contains gaseous dopants such as BF₃. Such dopants, however, can be easily removed by cleaning the film. Such an undoped film can be doped with other different dopants.

Such doping can be carried out, for instance, by (i) a doping method using Lewis acids such as I₂, Br₂, Cl₂, AsF₅ and SbF₅, (ii) a doping method using Brφnstead acids such as FSO₃ H, HNO₃, CF₃ SO₃ H, H₂ SO₄ and S₃ and (iii) an electrochemical doping method in which the doping is performed in an electrolytic solution of a salt comprising in combination a cation such as Li⁺, Na⁺, Ag⁺, EtN⁺, Bu₄ N⁺ and an anion such as ClO₄ ⁻, BF₄ ⁻, PF₆ ⁻ and AsF₆ ⁻.

The benzene polymer film obtained by the above method is uniform and stable in quality. The electroconductivity of the film can be increased by doping. Therefore it can find many different applications, for instance, for use as material for electrodes, semi-conductor, electrochromic material, electromagnetic shielding material and non-linear optical material.

Active Material Preparation Example 5

In an electrolytic chamber provided with an anode of Nesa glass (30 Ω/cm²) and a cathode of Ni as shown in FIG. 1, an electrolytic solution of benzene (0.1M) and a boron trifluoride diethyl ether complex (0.2M) dissolved in nitrobenzene was placed. Constant-current electrolysis with 5 mA/cm² was performed, so that a benzene polymer film No. 5 was prepared.

The thickness of the benzene polymer film No. 5 was 55 μm and the electroconductivity σ was 1.2×10⁻² S/cm (immediately after growth).

FIG. 2 shows an IR spectrum of the benzene polymer film No. 5. The IR spectrum of the benzene polymer film No. 5 indicates absorbance peaks at 701.97 cm⁻¹, 754.04 cm⁻¹, 806.11 cm⁻¹, 1002.81 cm⁻¹, 1481.08 cm⁻¹, 1598.72 cm⁻¹, 1710.57 cm³¹ 1 and 3027.73 cm⁻¹ which are characteristic of polyphenylene.

The benzene polymer film No. 5 was washed with water for undoping. FIG. 3 shows the IR spectrum of the undoped benzene polymer film No. 5.

Active Material Preparation Example 6

In the same electrolytic chamber provided with the anode of Nesa glass (30 Ω/cm²) and the cathode of Ni as that employed in Active Material Preparation Example 1, an electrolytic solution of benzene (0.1M) and a boron trifluoride diethyl ether complex (0.2M) dissolved in nitrobenzene was placed. Constant-current electrolysis with 1 mA/cm² was performed in an atmosphere of Ar gas (O₂ :1 ppm or less; the dew point: -81° C.), so that a benzene polymer film No. 6 was prepared. In the above preparation, the employed benzene and nitrobenzene were dehydrated by a molecular sieve and were then distilled under vacuum before use.

The thickness of the benzene polymer film No. 6 was 42 μm and the electroconductivity σ was 0.72×10⁻² S/cm (immediately after growth).

Active Material Preparation Example 7

In the same electrolytic chamber provided with the anode of Nesa glass (30 Ω/cm²) and the cathode of Ni as that employed in Active Material Preparation Example 1, an electrolytic solution of diphenyl (0.1M), a boron trifluoride diethyl ether complex (0.2M) and [(n-Bu₄ N)]⁺. (BF₄)⁻ (0.1M) dissolved in nitrobenzene was placed. Constant-voltage electrolysis with 10 V was performed, so that a benzene polymer film No. 7 was prepared.

The thickness of the benzene polymer film No. 7 was 12 μm and the electroconductivity σ was 1.6×10⁻³ S/cm (immediately after growth).

Active Material Preparation Example 8

In the same electrolytic chamber provided with the anode of Nesa glass (30 Ω/cm²) and the cathode of Ni as that employed in Active Material Preparation Example 1, an electrolytic solution of benzene (0.1M) and a boron trifluoride diethyl ether complex (0.1M) dissolved in dichloromethane was placed. Constant-current electrolysis with 7 mA/cm² was performed in such a condition as to exposed to the air, so that a benzene polymer film No. 8 was prepared.

The thickness of the benzene polymer film No. 8 was 38 μm and the electroconductivity σ was 2.6×10⁻² S/cm (immediately after growth).

Further, a polymerization method of using a transition metal complex, instead of the above-mentioned borontrifluoride complex, and an electrolyte containing an anion capable of producing a Lewis acid in the presence of the transition metal complex is also capable of yielding a benzene polymer for use in the present invention.

Examples of the transition metal complex are complexes containing a transition metal (such as Ni, Co, Cu, Cr, Mn, Fe and Zn) and coordination compounds containing a transition metal. Specific examples of coordination compounds containing a transition metal are NiCl₂ (PPh₃)₂, NiCl₂ (PPh₂ (allyl))₂, NiCl₂ (PPh(allyl))₂, CoCl₂ (PPh₃)₂, CoCl₂ (PPh₂ (allyl))₂, CoCl₂ (PPh(allyl))₂, Co(NH₃)₂ (NO₂)₃, Mn(NH₃)₆ (NO₃)₂, Cr(NH₃)₆ (NO₃)₂ and Sn(NH₃)₆ (NO₃)₂.

It is preferable that the content of such a complex in the electrolytic solution be in the range of 0.01 to 1.0M.

It is preferable to use as a monomer for this polymerization method benzene, diphenyl, naphthalene and anthracene which may have a halogen substituent (F, Cl, Br or I). Of these monomers, benzene and diphenly are most preferable for use.

It is preferable that the content of such monomer in the electrolytic solution be in the range of 0.05 to 1.0M.

The electrolytes that can be employed in this method are limited to particular electrolytic salts due to the use of the above-mentioned transition metal complexes. Specifically, the cations of the electrolytic salts are metal cations such as Na⁺, K⁺, Li⁺ and Ag⁺, organic cations such as (Bu)₄ N⁺ (tetrabutylammonium) and (Et)₄ N⁺ (tetraethylammonium), and the counterpart anions are such anions that are capable of producing Lewis acids, such as AsF₆, PF₆ ⁻, BF₆ ⁻ and SbF₆ ⁻ in the presence of the transition metal complex.

Specific examples of such electrolytes are LiPF₆, LiSbF₆, LiAsF₆, KPF₆, KSbF₆, AgBF₄, NaBF₄, NaAsF₆, NaPF₆, [(n-Bu)₄ N]. (AsF₆), [(n-Bu)₄ N]. BF₄, [(n-Bu)₄ N]. PF₆, [(n-Bu)₄ N]. SbF₆, [(n-Et)₄ N]. BF₄.

It is preferable that the content of such an electrolyte in the electrolytic solution be in the range of 0.05 to 1.0M.

As electrolytic solvents for this polymerization method, non-protonic solvents, such as acetonitrile, benzonitrile, propylene carbonate, γ-butyrolactone, dichloromethane, dichloroethane, dimethylformamide, nitromethane, nitroethane, and nitrobenzene, can be employed. Of these solvents, the most preferable solvents are solvents having small doner numbers of about 10 or less, for example, nitromethane, nitroethane, nitrobenzene, dichloroethane and dichloromethane.

As the materials for constructing the electrodes for the electrolytic polymerization, metals such as Au, Pt and Ni and metal oxides such as SnO₂ and In₂ O₃ can be employed. Further composite electrodes and coating electrodes comprising the above metal oxides can also be employed It is preferable that the anode be made of the metal oxide for obtaining a polymer film having high strength.

As the electrolytic chamber, a single electrolytic chamber provided with both cathode and anode in the chamber and a chamber with a cathode and an anode separately provided by a separator, can be employed. The above method can be carried out without difficulty in the single electrolytic chamber.

For electrolysis, constant-voltage elecrtrolysis, constant-current electrolysis and constant-potential electrolysis can all be employed Of these, constant-current electrolysis and constant-potential electrolysis are most suitable. In particular, constant-current electrolysis is suitable for mass production.

In the electrolysis, the adjustment of the current density is important since the current density has a significant effect on the morphology of the polymeric film to be made. Therefore it is necessary to make fine adjustment of the current density by appropriate combination of the electrolytes. It is preferable that the current density be in the range of 0.1 to 30 mA/cm².

The benzene polymer film obtained by the above method can be undoped chemically or electrochemically. The undoped benzene polymer film can be doped with many different kinds of dopants.

Such doping can be carried out, for instance, by (i) a doping method using Lewis acids such as I₂, Br₂, Cl₂, AsF₅ and SbF₅, (ii) a doping method using Brφnstead acids such as FSO₃ H, HNO₃, CF₃ SO₃ H, H₂ SO₄ and S₃ and (iii) an electrochemical doping method in which the doping is performed in an electrolytic solution of a salt comprising in combination a cation such as Li⁺, Na⁺, Ag⁺, EtN⁺, Bu₄ N⁺ and an anion such as ClO₄ ⁻, BF₄ ⁻, PF₆ ⁻ and AsF₆ ⁻.

Active Material Preparation Example 9

In the same electrolytic chamber provided with the anode of Nesa glass (30 Ω/cm²) and the cathode of Ni as that employed in Active Material Preparation Example 1, an electrolytic solution of benzene (0.1M), NiCl₂ (PPh(allyl))₂ (0.01M) and [Bu₄ N]. BF₄ (0.1M) dissolved in nitrobenezene was placed. Constant-current electrolysis with 15 mA/cm² was performed for 0.5 hours, so that a benzene polymer film No. 9 was obtained at the surface of the Nesa glass. The obtained benzene polymer film was glossy, brown and uniform in quality.

The thickness of the benzene polymer film No. 9 was 43 μm and the electroconductivity σ was 2.5×10⁻⁴ S/cm (immediately after growth).

An IR spectrum of this benzene polymer film indicated absorbance peaks at 690, 760, 800 and 1000 cm⁻¹ characteristic of polyphenylene.

Active Material Preparation Example 10

In the same electrolytic chamber provided with the anode of Nesa glass (30 Ω/cm²) and the cathode of Ni as that employed in Active Material Preparation Example 1, an electrolytic solution of benzene (0.1M), NiCl₂ (PPh₃)₂ (0.1M) and [Bu4N]. PF₆ (0.1M) dissolved in nitrobenzene was placed. Constant-current electrolysis with 1 mA/cm² was performed in an atmosphere of Ar gas (O₂ :1 ppm or less; the dew point: -81° C.) for 8 hours, so that a benzene polymer film No. 10 was prepared. In the above preparation, the employed benzene and nitrobenzene were dehydrated by a molecular sieve and were then distilled under vacuum before use.

The thickness of the benzene polymer film No. 10 was 42 μm and the electroconductivity σ was 1.6×10 S/cm (immediately after growth).

Active Material Preparation Example 11

In the same electrolytic chamber provided with the anode of Nesa glass (30 Ω/cm²) and the cathode of Ni as that employed in Active Material Preparation Example 1, an electrolytic solution of benzene (0.1M), CoCl₂ (PPh₃)₂ (0.2M) and [Bu₄ N].BF₄ (0.1M) dissolved in nitrobenezene was placed. Constant-voltage electrolysis with 20 V was performed for 0.5 hours, so that a benzene polymer film No. 11 was obtained.

The thickness of the benzene polymer film No. 11 was 29 μm and the electroconductivity σ was 5.3×10⁻³ S/cm (immediately after growth).

Active Material Preparation Example 12

In the same electrolytic chamber provided with the anode of Nesa glass (30 Ω/cm²) and the cathode of Ni as that employed in Active Material Preparation Example 1, an electrolytic solution of benzene (0.1M), Co(NH₃)₃ (NO₂)₃ (0.02M) and [Bu₄ N]. AsF₆ (0.1M) dissolved in nitrobenezene was placed. Constant-current electrolysis with 15 mA/cm² was performed for 0.5 hours with exposure to the air, so that a benzene polymer film No. 12 was obtained.

The thickness of the benzene polymer film No. 12 was 41 μm and the electroconductivity σ was 2.0×10⁻³ S/cm (immediately after growth).

Active Material Preparation Example 13

In the same electrolytic chamber provided with the anode of Nesa glass (30 Ω/cm²) and the cathode of Ni as that employed in Active Material Preparation Example 1, an electrolytic solution of benzene (0.1M), NiCl₂ (PPh₃)₂ (0.1M) and [Bu₄ N]. BF₄ (0.1M) dissolved in nitrobenezene was placed. Constant-current electrolysis with 1 mA/cm² was performed for 8 hours, so that a benzene polymer film No. 13 was obtained.

The thickness of the benzene polymer film No. 13 was 35 μm and the electroconductivity σ was 4.5 S/cm (immediately after growth).

Active Material Preparation Example 14

In the same electrolytic chamber provided with the anode of Nesa glass (30 Ω/cm²) and the cathode of Ni as that employed in Active Material Preparation Example 1, an electrolytic solution of benzene (0.1M), NiCl₂ (PPh₃)₂ (0.1M) and NaAsF₆ (0.1M) dissolved in dichloromethane was placed. Constant-current electrolysis with 10 mA/cm² was performed for 0.5 hours, so that a benzene polymer film No. 14 was obtained.

The thickness of the benzene polymer film No. 14 was 23 μm and the electroconductivity σ was 3.2×10⁻³ S/cm (immediately after growth).

Active Material Preparation Example 15

In the same electrolytic chamber provided with the anode of Nesa glass (30 Ω/cm²) and the cathode of Ni as that employed in Active Material Preparation Example 1, an electrolytic solution of diphenyl (0.1M), NiCl₂ (PPh₃)₂ (0.1M) and {Bu₄ N]. AsF₆ (0.1M) dissolved in nitrobenzene was placed. Constant-current electrolysis with 15 mA/cm² was performed for 0.5 hours, so that a benzene polymer film No. 15 was obtained.

The thickness of the benzene polymer film No. 15 was 35 μm and the electroconductivity σ was 2.2×10⁻² S/cm (immediately after growth).

In the organic secondary battery according to the present invention, as anode-active materials, for example, (i) polymers including conjugated double bonds of acetylene, pyrrole, thiophene, aniline, benzene, azulene and derivatives thereof, and (ii) polymer complexes of the above polymers and electrolytic anions which will be specifically mentioned later, can be employed. As mentioned previously, the benzene polymer employed as cathode-active material in the present invention can also be employed as anode-active material.

For fabrication of a thin type battery, it is preferable that the above polymers and polymer complexes be prepared by electrolytic polymerization.

When a polypyrrole complex is employed as anode-active material, it is preferable to use as its monomer pyrrole, 3,4-alkylpyrrole, 3,4-arylpyrrole, 3-alkyl-4-arylpyrrole and 4-alkyl-3-arylpyrrole. In such monomers, it is preferable that the alkyl be an alkyl group having 1 to 4 carbon atoms, and the aryl group be a phenyl group, a tolyl group and a xylyl group. Further such monomers are not limited to monomers, but dimers and trimers can also be employed. Hereinafter these starting materials are collectively referred to as the pyrrole-type monomers.

In preparation of the polypyrrole complexes, as electrolytic solvents, water, methanol, acetonitrile, benzonitrile, propylene carbonate, γ-butyrolactone, nitrobenzene, dioxane, dimethylformamide and acetone can be employed. In view of the reactivity and the strength of the polypyrrole complex film, acetonitrile, benzonitrile and propylene carbonate are most preferable for use.

As electrolytic anions for this polymerization method, inorganic anions such as ClO₄ ⁻, PF₆ ⁻, AsF₆ ⁻, CF₃ ⁻, SO₃ ⁻ and BF₄ ⁻, and unsubstituted and substituted aromatic anions such as aromatic sulfonic acids and aromatic carboxylic acids, which may have one or more identical or different substituents such as an alkyl group having 1 to 3 carbon atoms, a nitro group and a cyano group (for example; p-toluene sulfonic acid and nitrobenzene sulfonic acid) are preferable for use.

As counterpart cations, alkali metal cations such as Na⁺, K⁺ and Li⁺, ammonium cations such as (C₂ H₅)₄ N⁺, (C₄ H₉)₄ N⁺, (C₆ H₁₃)₄ N⁺, and H⁺ are preferable for use.

The polypyrrole complex film is prepared by subjecting the above-mentioned pyrrole-type mononer to electrolytic polymerization in the presence of an electrolyte comprising the above-mentioned anion and cation Upon causing an electric current to flow through a solution of the pyrrole-type monomer and the electrolyte dissolved in one of the above-mentioned solvents, the polyryrrole complex film is readily formed. It is preferable that the current density in the above electrolytic polymerization be in the range of about 0.1 to 1.5 mA/cm² and the content of the pyrrole-type monomenr in the electrolytic solution be in the range of 0.02 to 1.00M, more preferably in the range of 0.10 to 0.30 for obtaining an uniform film with high yield.

In the above electrolytic polymerization, it is preferable that the polymerization be performed in the presence of both the aromatic anion and the inorganic anion. This is because when both aromatic anion and inorganic anion are present, the obtained polypyrrole complex film can be doped and undoped with its film strength maintained high, so that when it is employed as anode-active material in an organic secondary battery, high recharging and discharging performance can be attained.

In this method, it is preferable that the current density be in the range of about 1.0 to 1.5 mA/cm² in view of the reactivity in the polymerization, the uniformity, strength and thickness of the obtained film.

It is preferable that the content of the aromatic anion be in the range of 0.01 to 0.2M in view of the polymerization efficiency and the mechanical strength of the obtained film.

Further it is preferable that the molar content ratio of the aromatic anion to the inorganic anion in the electrolytic solution be (1) : (about 0.2 to 2) for obtaining appropriate current density and a film having high mechanical strength In other words, it is preferable that the ratio be 1M of the aromatic anion to about 0.2 to 2M of the inorganic anion.

The above polymerization is performed by placing a solution comprising the pyrrole-type monomer, an aromatic anion salt, an inorganic anion salt and a solvent in an electrolytic chamber, immersing a cathode and an anode in the solution, and then performing an electrolytic polymerization with anodic oxidation by causing an electric current to flow therethrough.

As the materials for constructing the electrodes for the electrolytic polymerization, metals such as Au, Pt and Ni and metal oxides such as SnO₂ and In₂ O₃ can be employed. Further composite electrodes and coating electrodes comprising the above metals and/or metal oxides can also be employed. It is preferable that the anode be made of the metal oxide for obtaining a polypyrrole complex film having high strength.

Active Material Preparation Example 15

In the same electrolytic chamber provided with the anode of Nesa glass (30 Ω/cm²) and the cathode of Ni as that employed in Active Material Preparation Example 1, an electrolytic solution of pyrrole (0.1M), sodium nitrobenzene sulfonate (0.03M) and tetrabutylammonium tetrafluoroborate (0.03M) dissolved in acetonitrile was placed. Constant-voltage electrolysis with 4.0 V (current density 2.5 mA/cm²) was performed, so that a polypyrrole film No. 1 was obtained.

Active Material Preparation Example 16

In the same electrolytic chamber provided with the anode of Nesa glass (30 Ω/cm²) and the cathode of Ni as that employed in Active Material Preparation Example 1, an electrolytic solution of pyrrole (0.1M), sodium p-toluene sulfonate (0.05M) and tetrabutylammonium tetrafluoroborate (0.03M) dissolved in acetonitrile was placed. Constant-voltage electrolysis with 4.0 V (current density 2.5 mA/cm²) was performed, so that a polypyrrole film No. 2 was obtained.

Active Material Preparation Example 17

In the same electrolytic chamber provided with the anode of Nesa glass (30 Ω/cm²) and the cathode of Ni as that employed in Active Material Preparation Example 1, an electrolytic solution of pyrrole (0.1M) and NaAsF₆ (0.2M) dissolved in acetonitrile was placed. Constant-current electrolysis with 2 mA/cm² was performed, so that a polypyrrole film No. 3 was prepared.

Active Material Preparation Example 18

In the same electrolytic chamber provided with the anode of Nesa glass (30 Ω/cm²) and the cathode of Ni as that employed in Active Material Preparation Example 1, an electrolytic solution of azulene (0.005M) and AgClO₄ (0.1M) dissolved in acetonitrile was placed. Constant-current electrolysis with 15 mA/cm² was performed, so that a polyazulene film No. 1 was prepared.

Active Material Preparation Example 19

In the same electrolytic chamber provided with the anode of Nesa glass (30 Ω/cm²) and the cathode of Ni as that employed in Active Material Preparation Example 1, an electrolytic solution of thiophene (0.1M) and LiClO₄ (0.2M) dissolved in acetonitrile was placed. Constant-current electrolysis with 5 mA/cm² was performed, so that a polythiophene film No. 1 was prepared.

Active Material Preparation Example 20

An acetylene gas was blown against the surface of a Ziegler-Natta catalyst (Ti(OC₄ H₉)₄ -Al(C₂ H₅)₃) liquid in an atmosphere of argon in accordance with the conventionally known method called "Shirakawa Method" (for example, described in Polymer Journal No. 2,231 (1971)), whereby a polyacetylene film No. 1 with a thickness of about 200 μm was obtained.

To the electrodes of the organic secondary battery according to the present invention, a current collector made of a sheet of Al, Ni, Pt, Au or Ag can be applied to the respective active materials with pressure, adhesion, vacuum deposition or sputtering. The current collector can also be made of the above-mentioned polypyrrole film.

A separator disposed between the anode and the cathode of the organic secondary battery according to the present, invention can be made of a glass fiber filter, a polymeric pore filter (made of polyester, teflon, polypropylene or polyfuran), or a non-woven fabric of a glass fiber and the polymer such as polyester, teflon, polypropylene or polyfuran.

A polyfuran complex, which is a complex comprising a furan monomer units and anions, can be used as the separator for the organic secondary battery according to the present invention.

As a furan monomer for use in the polyfuran complex, for example, the following can be employed: ##STR1## wherein R¹ and R² each represent hydrogen, an alkyl group or alkoxy group having 1 to 2 carbon atoms, or a halogen, and n is an integer of 1 to 3.

The polyfuran complex can be prepared by an electrolytic polymerization by causing electric current to flow through an electrolytic solution of a furan-type monomer and an electrolyte dissolved in an organic solvent.

As the electrolytes for this polymerization, electrolytic salts comprising the following cations and anions can be employed:

Examples of the cations are alkali metal cations, for instance, Li⁺, Na⁺ and K⁺ ; ammonium cations, and H⁺. Examples of the anions are halogenated anions of Va-group elements, for instance, PF₆ ⁻, SbF₆ ⁻, AsF₆ ⁻ and SbCl₆ ⁻, halogenated anions of IIIa-group elements, such as BF₄ ⁻, and perchlorate anions such as ClO₄ ⁻.

Specific examples of such electrolyte salts are LiPF₆, LiSbF₆, LiAsF₆, LiClO₄, LiAlCl₄, LiBF₄, NaClO₄, KI, KPF₆, KSbF₆, KAsF₆, KClO₄, NaBF₄, NaAsF₆, NaPF₆, AgBF₄, AgClO₄, [(n-Bu)₄ N]⁺. (AsF₆ ⁻, [(n-Et)₄ N]⁺. ClO₄ ⁻, [(n-Bu)₄ N]⁺. ClO₄ ⁻.

Of these electrolyte salts, LiClO₄, AgClO₄ and KClO₄ are particularly preferable for the formation of an excellent polyfuran complex film.

It is preferable that the content of a furan-type monomer in the electrolytic solution be in the range of about 0.02 to 1.00M, more preferably in the range of about 0.10 to 0.30M.

Further, it is preferable that the content of the electrolytic salts in the electrolytic solution be about 1.0M or less for obtaining a polyfuran film with high uniformity in quality.

As electrolytic solvents for this polymerization method, non-protonic solvents, such as acetonitrile, benzonitrile, propylene carbonate, γ-butyrolactone, dichloromethane, nitrobenzene, nitromethane, nitroethane, dichloromethane, dioxane, dimethylforamide, can be employed. Of these solvents, acetonitrile and propylene carbonate are preferable. Benzonitrile is particularly preferable. Further, it is preferable that no water and oxygen be contained in the solvents for obtaining an uniform polymer complex film.

The above polymerization is performed by placing a solution comprising the furan-type monomer and the electrolytic salt dissolved in the above-mentioned solvent in an electrolytic chamber, immersing a cathode and an anode in the solution, and performing an electrolytic polymerization with anodic oxidation by causing an electric current to flow therethrough.

As the materials for constructing the electrodes for the electrolytic polymerization, metals such as Au, Pt and Ni and metal oxides such as SnO₂ and In₂ O₃ can be employed Further composite electrodes and coating electrodes comprising the above metal oxides can also be employed It is preferable that the anode be made of such a metal oxide for obtaining a polyfuran complex film having high strength.

A polyfuran complex film obtained in the above described method has an extremely small electron conductivity with an electroconductivity of 10⁻⁵ S/m in a dry state, but has high ion-conductivity.

It is preferable that the polyfuran complex film be about 10 to 250 μm thick.

Battery Example 1

An anode was prepared by applying to a Ni foil with pressure a polypyrrole film (4 mg/cm²) (serving as an anode-active material) prepared in Active Material Preparation Example 5.

A cathode was prepared by applying to a Ni foil with pressure a benzene polymer film (12 mg/cm²) (serving as a cathode-active material) prepared in Active Material Preparation Example 1.

As an electrolytic solution, LiClO₄ (1M)/propylene carbonate was employed.

A separator was made of a polypropylene carbonate non-woven fabric, an external film was made of a 120 μm thick biaxial drawing polyester film, and a sealing material was made of Chemistat R99 (made by Toray Industries, Inc.

The anode, the cathode, the electrolytic solution, the separator and the sealing material were assembled as shown in FIG. 2, so that an organic secondary battery No. 1 of a thin sheet-type was fabricated. External electrodes (not shown) were constructed by spot-welding Ni-lead wires to Ni foil current collectors (not shown).

The organic secondary battery No. 1 was evaluated with respect to the following points:

(1) Open-circuit Voltage (V)

The voltage across the two electrode was measured (i) immediately after recharging and (ii) one week after recharging.

(2) Energy Density (Wh/kg)

This was measured by recharging and discharging with a constant current (0.5 mA).

(3) Short-circuit Current (mA/cm²)

This was measured one week after recharging.

The results of the evaluation of the battery No. 1 were as follows:

    ______________________________________                                         Battery No. 1                                                                  ______________________________________                                         Battery Elements                                                               Anode-active Material                                                                           Polypyrrole Film                                                               (Active Material Preparation                                                   Example 5)                                                    Cathode-active Material                                                                         Benzene Polymer No. 1                                                          (Active Material Preparation                                                   Example 1)                                                    Electrolytic Solution                                                                           LiClO.sub.4 (1 M)/Propylene                                                    carbonate                                                     ______________________________________                                         Results of Evaluation                                                          Open-circuit Voltage                                                           Immediately after    2.9    V                                                  recharging                                                                     One week after       2.7    V                                                  recharging                                                                     Short-circuit        2.2    mA/cm.sup.2                                        Current                                                                        Energy Density       188    Wh/kg                                              ______________________________________                                    

Battery Example 2

An organic secondary battery No. 2 was fabricated in the same manner as in Battery Example 1 except the battery elements were changed as shown in the following table and the fabricated battery No. 2 was evaluated in the same manner as in Battery Example 1. The results are also shown in the following table:

    ______________________________________                                         Battery No. 2                                                                  ______________________________________                                         Battery Elements                                                               Anode-active Material                                                                           Polypyrrole Film                                                               (Active Material Preparation                                                   Example 5)                                                    Cathode-active Material                                                                         Benzene Polymer No. 2                                                          (Active Material Preparation                                                   Example 2)                                                    Electrolytic Solution                                                                           LiBF.sub.4 (1 M)/Propylene                                                     carbonate                                                     ______________________________________                                         Results of Evaluation                                                          Open-circuit Voltage                                                           Immediately after    2.8    V                                                  recharging                                                                     One week after       2.8    V                                                  recharging                                                                     Short-circuit        2.0    mA/cm.sup.2                                        Current                                                                        Energy Density       163    Wh/kg                                              ______________________________________                                    

Battery Example 3

An organic secondary battery No. 3 was fabricated in the same manner as in Battery Example 1 except the battery elements were changed as shown in the following table and the fabricated battery No. 3 was evaluated in the same manner as in Battery Example 1. The results are also shown in the following table:

    ______________________________________                                         Battery No. 3                                                                  ______________________________________                                         Battery Elements                                                               Anode-active Material                                                                           Benzene Polymer No. 3                                                          (Active Material Preparation                                                   Example 3)                                                    Cathode-active Material                                                                         Benzene Polymer No. 3                                                          (Active Material Preparation                                                   Example 3)                                                    Electrolytic Solution                                                                           LiClO.sub.4 (1 M)/Propylene                                                    carbonate                                                     ______________________________________                                         Results of Evaluation                                                          Open-circuit Voltage                                                           Immediately after    3.3    V                                                  recharging                                                                     One week after       2.9    V                                                  recharging                                                                     Short-circuit        2.5    mA/cm.sup.2                                        Current                                                                        Energy Density       146    Wh/kg                                              ______________________________________                                    

Battery Example 4

An organic secondary battery No. 4 was fabricated in the same manner as in Battery Example 1 except the battery elements were changed as shown in the following table and the fabricated battery No. 4 was evaluated in the same manner as in Battery Example 1. The results are also shown in the following table:

    ______________________________________                                         Battery No. 4                                                                  ______________________________________                                         Battery Elements                                                               Anode-active Material                                                                           Polyazulene Film                                                               (Active Material Preparation                                                   Example 18)                                                   Cathode-active Material                                                                         Benzene Polymer No. 1                                                          (Active Material Preparation                                                   Example 1)                                                    Electrolytic Solution                                                                           LiClO.sub.4 (1 M)/Propylene                                                    carbonate                                                     ______________________________________                                         Results of Evaluation                                                          Open-circuit Voltage                                                           Immediately after    2.8    V                                                  recharging                                                                     One week after       2.6    V                                                  recharging                                                                     Short-circuit        2.4    mA/cm.sup.2                                        Current                                                                        Energy Density       144    Wh/kg                                              ______________________________________                                    

Comparative Battery Example 1

A comparative organic secondary battery No. 1 was fabricated in the same manner as in Battery Example 1 except the battery elements were changed as shown in the following table and the comparative battery No. 1 was evaluated in the same manner as in Battery Example 1. The results are also shown in the following table:

    ______________________________________                                         Comparative Battery No. 1                                                      ______________________________________                                         Battery Elements                                                               Anode-active Material                                                                           Polypyrrole Film                                                               (Active Material Preparation                                                   Example 17)                                                   Cathode-active Material                                                                         Polythiophene Film                                                             (Active Material Preparation                                                   Example 19)                                                   Electrolytic Solution                                                                           LiClO.sub.4 (1 M)/Propylene                                                    carbonate                                                     ______________________________________                                         Results of Evaluation                                                          Open-circuit Voltage                                                           Immediately after    2.3   V                                                   recharging                                                                     One week after       1.6   V                                                   recharging                                                                     Short-circuit        2.0   mA/cm.sup.2                                         Current                                                                        Energy Density       65    Wh/kg                                               ______________________________________                                    

Comparative Battery Example 2

A comparative organic secondary battery No. 2 was fabricated in the same manner as in Battery Example 1 except the battery elements were changed as shown in the following table and the comparative battery No. 2 was evaluated in the same manner as in Battery Example 1. The results are also shown in the following table:

    ______________________________________                                         Comparative Battery No. 2                                                      ______________________________________                                         Battery Elements                                                               Anode-active Material                                                                           Polythiophene Film                                                             (Active Material Preparation                                                   Example 19)                                                   Cathode-active Material                                                                         Polythiophene Film                                                             (Active Material Preparation                                                   Example 19)                                                   Electrolytic Solution                                                                           LiClO.sub.4 (1 M)/Propylene                                                    carbonate                                                     ______________________________________                                         Results of Evaluation                                                          Open-circuit Voltage                                                           Immediately after    1.6   V                                                   recharging                                                                     One week after                                                                 recharging           1.2   V                                                   Short-circuit        3.0   mA/cm.sup.2                                         Current                                                                        Energy Density       80    Wh/kg                                               ______________________________________                                    

Comparative Battery Example 3

A comparative organic secondary battery No. 3 was fabricated in the same manner as in Battery Example 1 except the battery elements were changed as shown in the following table and the comparative battery No. 3 was evaluated in the same manner as in Battery Example 1. The results are also shown in the following table:

    ______________________________________                                         Comparative Battery No. 3                                                      ______________________________________                                         Battery Elements                                                               Anode-active Material                                                                           Polyacetylene Film                                                             (Active Material Preparation                                                   Example 20)                                                   Cathode-active Material                                                                         Polyacetylene Film                                                             (Active Material Preparation                                                   Example 20)                                                   Electrolytic Solution                                                                           LiClO.sub.4 (1 M)/Propylene                                                    carbonate                                                     ______________________________________                                         Results of Evaluation                                                          Open-circuit Voltage                                                           Immediately after    2.7    V                                                  recharging                                                                     One week after       1.6    V                                                  recharging                                                                     Short-circuit        5.1    mA/cm.sup.2                                        Current                                                                        Energy Density       132    Wh/kg                                              ______________________________________                                    

The organic secondary batteries Nos. 1 to 4 are more stable in performance and smaller in self-discharge and have higher energy densities as compared with the comparative batteries Nos. 1 to 3.

Battery Example 5

An anode was prepared by applying to a Ni foil with pressure a polypyrrole film (4 mg/cm²) (serving as an anode-active material) prepared in Active Material Preparation Example 15.

A cathode was prepared by applying to a Ni foil with pressure a benzene polymer film (12 mg/cm²) (serving as a cathode-active material) prepared in Active Material Preparation Example 1.

As an electrolytic solution, LiBF₄ (1M) was employed.

A separator was made of a polypropylene carbonate non-woven fabric, an external film was made of a 120 μm thick biaxial drawing polyester film, and a sealing material was made of Chemistat R99 (made by Toray Industries, Inc.

The anode, the cathode, the electrolytic solution, the separator and the sealing material were assembled as shown in FIG. 2, so that an organic secondary battery No. 5 of a thin sheet-type was fabricated. External electrodes (not shown) were constructed by spot-welding Ni-lead wires to Ni foil current collectors (not shown).

The thus fabricated organic secondary battery No. 5 was as good as the organic secondary battery No. 1 with respect to the open-circuit voltage, energy density, short-circuit current and life time.

Battery Example 6

Battery Example 5 was repeated except the polypyrrole film No. 1 employed in Battery Example 5 was replaced by the polypyrrole film No. 2 prepared in Active Material Preparation Example 16, so that an organic secondary battery No. 6 was fabricated.

The thus fabricated organic secondary battery No. 5 was as good as the organic secondary battery No. 1 with respect to the open-circuit voltage, energy density, short-circuit current and life time.

Battery Example 7

In the same electrolytic chamber provided with the anode of Nesa glass (30 Ω/cm²) and the cathode of Ni as that employed in Active Material Preparation Example 1, an electrolytic solution of pyrrole (0.1M) and NaAsF₆ (0.2M) dissolved in acetonitrile was placed. Constant-current electrolysis with 2 mA/cm² was performed, so that a polypyrrole film having a thickness of about 50 μm was formed on the Nesa glass.

In this electrolytic chamber, a solution of furan (0.05M) and LiClO₄ (0.2M) dissolved in benzonitrile was placed. Constant-voltage electrolysis with 6.5 V was then performed, so that a polyfuran flim having a thickness of about 35 μm was formed on the polypyrrole film. The layered polypyrrole film and polyfuran film were peeled off the Nesa glass at the same time, so that a composite film consisting of the polypyrrole film and the polyfuran film was prepared.

The benzene polymer film No. 1 prepared in Active Preparation Example 1 was then applied to the polyfuran film side of the composite film. This was then held between a pair of a nickel plate holders and immersed in an electrolytic solution of LiClO₄ (1M) dissolved in propylene carbonate, whereby an organic secondary battery No. 7 having a structure as shown in FIG. 4 was fabricated. In this battery, the polypryrole film worked as anode-active material, the polyfuran film as separator and the benzene polymer film No. 1 as cathode-active material.

The thus fabricated organic secondary battery No. 7 was as good as the organic secondary battery No. 1 with respect to the open-circuit voltage, energy density, short-circuit current and life time.

Battery Example 8

In the same electrolytic chamber provided with the anode of Nesa glass (30 Ω/cm²) and the cathode of Ni as that employed in Active Material Preparation Example 1, an electrolytic solution of furan (0.05M) and AgClO₄ (0.2M) dissolved in benzonitrile was placed. Constant-voltage electrolysis with 4.0 V was performed, so that a polyfuran film having a thickness of about 45 m was formed on the Nesa glass.

An acetylene gas was blown against the surface of a Ziegler-Natta catalyst (Ti(OC₄ H₉)₄ -Al(C₂ H₅)₃) liquid in an atmosphere of argon in accordance with the conventionally known method called "Shirakawa Method" (for example, described in Polymer Journal No. 2,231 (1971)), whereby a polyacetylene film No. 1 with a thickness of about 200 μm was obtained.

On a benzene polymer film No. 2 prepared in Active Material Preparation Example 2, the above prepared polyfuran film and the polyacetylene film were successively applied, so that an organic secondary battery No. 8 according to the present invention was prepared in the same manner as in Battery Example 7 having the structure as shown in FIG. 4. In this battery, the polyacetylene film worked as anode-active material, the polyfuran film as separator and the benzene polymer film No. 2 as cathode-active material.

The thus fabricated organic secondary battery No. 8 was as good as the organic secondary battery No. 1 with respect to the open-circuit voltage, energy density, short-circuit current and life time. 

What is claimed is:
 1. A method of producing a benzene polymer by electrolytic polymerization comprising anodically oxidizing benzene or a benzene derivative monomer selected from the group consisting of halogenated benzene, diphenyl and halogenated diphenyl in an electrolytic solution comprising an electrolyte and a solvent.
 2. The method of producing a benzene polymer as recited in claim 1, wherein said electrolyte is selected from the group consisting of LiPF₆, LiSbF₆, LiAsF₆, LiClO₄, NaClO₄, KI, KPF₆, KSbF₆, KAsF₆, KClO₄, AgBF₄, NaBF₄, NaAsF₆, NaPF₆, [(n-Bu)N]⁺. (AsF₆)⁻ and [(n-Bu)₄ N]⁺. (ClO₄)⁻.
 3. The method of producing a benzene polymer as recited in claim 1, wherein said electrolyte is selected from the group consisting of FeCl₃, AlCl₃, ZnCl₂ and AlBr₃.
 4. The method of producing a benzene polymer as recited in claim 1, wherein said electrolytic solution further comprises a transition metal complex and said electrolyte contains an anion capable of producing ,a Lewis acid in the presence of said transition metal complex.
 5. The method of producing a benzene polymer as recited in claim 1, wherein said solvent is selected from the group consisting of acetonitrile, benzonitrile, propylene carbonate, γ-butyrolactone, dichloromethane, dioxane, dimethylformamide, nitromethane, nitroethane, nitropropane and nitrobenzene.
 6. The method of producing a benzene polymer as recited in claim 1, wherein said solvent is a nitro compound solvent having a doner number of less than about
 10. 7. The method of producing a benzene polymer as recited in claim 4, wherein said transition metal complex is selected from the group consisting of NiCl₂ (PPh₃)₂, NiCl₂ (PPh₂ (allyl))₂, NiCl₂ (PPh(allyl))₂, CoCl₂ (PPh₃)₂, CoCl₂ (PPh₂ (allyl))₂, CoCl₂ (PPh(allyl))₂, Co(NH₃)₂ (NO₂)₃, Mn(NH₃)₆ (NO₃)₂, Cr(NH₃)₆ (NO₃)₂ and Sn(NH₃)₆ (NO₃)₂.
 8. The method of producing a benzene polymer as recited in claim 4, wherein said anion is selected from the group consisting of AsF₆ ⁻, PF₆ ⁻, BF₆ ⁻ and SbF₆ ⁻.
 9. The method of producing a benzene polymer s recited in claim 4, wherein said electrolyte is selected from the group consisting of LiPF₆, LiSbF₆, LiAsF₆, KPF₆, KSbF₆, AgBF₄, NaBF₄, NaAsF₆, NaPF₆, [(n-Bu)₄ N]⁺. (AsF₆)⁻, [(n-Bu)₄ N]⁺. (BF₄)⁻, [(n-Bu)₄ N]⁺. (PF₆)⁻, [(n-Bu)₄ N]⁺. (SbF₆)⁻ and [(n-Et)₄ N]⁺. (BF₄)⁻.
 10. A method of producing a benzene polymer by electrolytic polymerization comprising anodically oxidizing benzene or a benzene derivative monomer selected from the group consisting of halogenated benzene, diphenyl and halogenated diphenyl in an electrolytic solution comprising a boron trifluoride complex and a solvent.
 11. The method of producing a benzene polymer as recited in claim 10, wherein said boron trifluoride complex is selected from the group consisting of BF₃ methanol complex, BF₃ ethanol complex, BF₃ propanol complex, BF₃ dimethyl ether complex, BF₃ diethyl ether complex, BF₃ phenol complex and BF₃ acetic acid complex.
 12. The method of producing a benzene polymer as recited in claim 10, wherein said solvent is selected from the group consisting of acetonitrile, benzonitrile, propylene carbonate, γ-butyrolactone, dichloromethane, dichloroethane, dimethylformamide, nitromethane, nitroethane and nitrobenzene.
 13. The method of producing a benzene polymer as recited in claim 10, wherein said electrolytic solution further comprises an electrolyte selected from the group consisting of LiPF₆, LiSbF₆, LiAsF₆, LiClO₄, NaClO₄, KI, KPF₆, KSbF₆, KClO₄, AgBF₄, NaBF₄, NaAsF₆, NaPF₆, [(n-Bu)₄ N]⁺. (BF₄)⁻, [(n-Bu)₄ N]⁺. (AsF₆)⁻ and [(n-Bu)₄ N]⁺. (ClO₄)⁻. 